[mycelium]

I try to shift from Ruby (on Rails) to to Clojure. But I feel hard to rewrite mountains of RoR convieniece and habits into Clojure (1.day.ago, named routes, ActiveMailer, encrypted cookie etc).

This seems like a bad idea from a business value perspective. What value is delivered by translating mountains of code? Probably none, being honest.

As I am also partially Java guy, I came to conclusion that migration of project into JRuby and then embedding Clojure parts gradually might ease the transition.

Don't transition everything, giant waste of time. Run ruby/rails on jruby, then package the core Clojure logic up as a library, and call into it from rails where needed. Clojure is your core logic, ruby/rails is the web front end to that core.